Glover M. Allen, Animal Figures in the Maya Codices
“ The animal head is frequently attached to a human body. The animal may appear conventionalized to a greater or less extent and the head in turn may change in the same way until only a single characteristic of the animal remains by which to identify it as, for example, the spots of the jaguar or the feathering around the eye of the macaw. In the case of the glyphs, a term employed to designate the regular and usually square characters appearing in lines or columns throughout the codices and inscriptions, we find both the realistic drawing and that where conventionalism has come in. ”
